WIKA S-20 Industrial Pressure Transmitter 0.4 to 1,600 bar

WIKA S-20 pressure transmitter for demanding industrial applications

The WIKA S-20 is a configurable industrial pressure transmitter for harsh environments and critical duty, with measuring ranges from 0 … 0.4 bar to 0 … 1,600 bar [0 … 5.8 to 0 … 23,200 psi]. The manufacturer says that the combinations of range, output signal, electrical connection and process connection allow more than a billion versions, and common versions can be delivered from a batch size of one. WIKA also states up to 100 million load cycles and a long-term stability of less than 0.1 %. Seven Star LLC supplies the S-20 in Oman and the GCC as an independent supplier in Muscat, and this page shows how to read the options so that an RFQ describes one exact version.

Key capabilities of the S-20

Three accuracy classes are offered, defined by non-linearity: ≤ ±0.5 %, ≤ ±0.25 % and ≤ ±0.125 % of span (best fit straight line per IEC 61298-2). The corresponding maximum measured errors per IEC 61298-2 are ≤ ±1 %, ≤ ±0.5 % and ≤ ±0.25 % of span. The tightest class is restricted to 4 … 20 mA and DC 0 … 10 V outputs. Another selectable feature is the adjustment temperature: standard 15 … 25 °C, or 4, 40, 60 or 80 °C ± 5 °C, which moves the best accuracy point toward the real working temperature and reduces temperature error.

Versions for special media include oxygen and hydrogen service, high temperatures and high cleanliness; ingress protection can reach IP68 and IP6K9K. Leak rate is below 5·10-3 mbar l/s, or below 1·10-6 mbar l/s for oxygen and hydrogen and for hazardous fluids as defined in the pressure equipment directive.

Technical specifications of the S-20

Process and electrical connections of the S-20

The S-20 data sheet is unusually broad on process connections. Metric and imperial parallel threads include G 1/4 A and G 1/2 A (DIN EN ISO 1179-2), M14 x 1.5, G 1/8 B, G 1/4 B, G 3/8 B and G 1/2 B (EN 837), DIN 16288 M12 x 1.5 and M20 x 1.5, and SAE J514 types. Taper threads include 1/8, 1/4 and 1/2 NPT, R 1/4, R 3/8, R 1/2 and Korean PT sizes. For above 1,000 bar there are M16 x 1.5 female, 9/16-18 UNF F250-C female, 1/2 NPT, G 1/2 B and M20 x 1.5 connections up to 1,600 bar. Pressure port diameters range from 0.3 mm to 12 mm, wider ports being limited to ranges up to 40 bar. Seal choices are NBR, FKM/FPM, EPDM or copper and stainless steel washers, each with its own temperature limit, for example NBR -30 … +100 °C and FKM -40 … +200 °C.

Electrical connections include angular connector DIN EN 175301-803 A and C, M12 x 1 four-pin circular connector in plastic or metal, bayonet connector, a field case for IP6K9K and a range of cable outlets, including IP68 versions in PUR or FEP and a 1/2 NPT conduit version. Output signal damping and signal clamping (3.6 or 3.8 mA) can be selected. The switch-on time is 150 ms.

Where the S-20 fits and related WIKA transmitters

WIKA lists the A-10 as the general-purpose transmitter for less demanding duty, the S-11 for flush diaphragm connections on viscous media, the IS-3 for hazardous areas and the HP-2 for the highest pressures. The S-20 is the broad industrial standard between them. Isolation and protection accessories such as the 910.11 valve, 910.12 snubber and 910.13 overpressure protector are installed upstream of the process connection when pulsation or surges are expected. Sealing rings per 910.17 are suitable for the parallel thread connections.

Selection and ordering checklist for the S-20

• Gauge, absolute or vacuum range, and the maximum working pressure, which equals the upper range value.
• Accuracy class and adjustment temperature that match the real process temperature.
• Output signal and supply voltage of the receiving system.
• Process connection, pressure port diameter and seal material.
• Medium and ambient temperature, with cooling element if above 125 °C.
• Electrical connection and ingress protection (IP65, IP67, IP68, IP6K9K).
• Special media: oxygen, hydrogen, high cleanliness.
• Certificates: 2.2 test report, 3.1 inspection certificate or factory calibration certificate.

Installation, commissioning and maintenance of the S-20

Install with the overpressure limit in mind: it is three times the range up to 16 bar and two times above, with lower factors at specific ranges such as 1.45 times at 1,000 bar. Never operate permanently above the maximum working pressure. A higher overpressure limit comes with a higher temperature error. On measuring ranges of 1 bar or below, an additional zero offset of up to 1 mbar can arise depending on mounting position, so state the installed position at order. Where a cooling element is fitted, apply the derating relation of the data sheet between medium and ambient temperature. Use a mating connector with the same IP rating as the transmitter, because the stated IP code only applies when plugged in correctly.

Typical applications in Oman and the GCC

The S-20 suits hot, dusty and humid process plants: compressor skids, hydraulic and lubrication units, water injection, heat exchangers, desalination high-pressure pumps, steam condensate lines and test rigs. Its wide choice of process connection reduces the need for adapters when replacing older transmitters on existing tappings, which is useful in long-life oil and gas and power plants where a like-for-like fit matters.

Accuracy classes of the S-20

Information to send with an RFQ

• S-20 with range, pressure type and unit
• Accuracy class and adjustment temperature
• Output signal and supply
• Process connection, port and seal
• Electrical connection and IP rating
• Media and temperatures; special cleanliness
• Quantity, certificates and delivery site

Documents and quotation

The WIKA data sheet for the S-20 is attached on this page and holds the full range, connection and approval tables.

Send the range, output, connection and quantity and Seven Star LLC will confirm availability and a quotation.